hello. i'm trying to make a scene with the dust in the air. i followed these instructions: "make a spot light, then attach fog to it. In the fog's properties, map a 3D fractal node to the density." but that doesn't work. i'm using vray for maya and tried to do this with vray rect light. got no errors, but no effect too. then i tried to do the same with simple spot light, and got error message "Warning: Unsupported texture kLightFogMaterial". no effect also.